net.sf.tweety.machinelearning.assoc

Class AssociationRule<T>

java.lang.Object

net.sf.tweety.machinelearning.assoc.AssociationRule<T>

Type Parameters:

T - The type of items.

public class AssociationRule<T>
extends Object

An association rule in item set mining.

Author:

Matthias Thimm

Constructor Summary

Constructors

Constructor and Description
AssociationRule() Creates a new empty association rule.
AssociationRule(Collection<T> premise, Collection<T> conclusion) Creates a new association rule with the given premise and conclusion

Method Summary

Modifier and Type	Method and Description
boolean	addToConclusion(T t) Adds the given object to the conclusion.
boolean	addToPremise(T t) Adds the given object to the premise.
double	confidence(Collection<Collection<T>> database) Returns the confidence of this rule wrt.
Collection<T>	getConclusion() Returns the conclusion of this rule.
Collection<T>	getPremise() Returns the premise of this rule.
double	support(Collection<Collection<T>> database) Returns the support of this rule wrt.
static <S> double	support(Collection<S> itemset, Collection<Collection<S>> database) Returns the support of the given itemset wrt.
static <S> double	support(S item, Collection<Collection<S>> database) Returns the support of the given item wrt.
String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

AssociationRule

public AssociationRule()

Creates a new empty association rule.

AssociationRule

public AssociationRule(Collection<T> premise,
                       Collection<T> conclusion)

Creates a new association rule with the given premise and conclusion

Parameters:

premise - some set of objects for the premise.

conclusion - some set of objects for the conclusion.

Method Detail

addToPremise

public boolean addToPremise(T t)

Adds the given object to the premise.

Parameters:

t - some object

Returns:

"true" iff this has been changed.

addToConclusion

public boolean addToConclusion(T t)

Adds the given object to the conclusion.

Parameters:

t - some object

Returns:

"true" iff this has been changed.

getPremise

public Collection<T> getPremise()

Returns the premise of this rule.

Returns:

the premise of this rule.

getConclusion

public Collection<T> getConclusion()

Returns the conclusion of this rule.

Returns:

the conclusion of this rule.

support

public static <S> double support(S item,
                                 Collection<Collection<S>> database)

Returns the support of the given item wrt. the given database, i.e., the number of transactions of the database, which contain the given item, divided by the number of all transactions.

Parameters:

item - some object

database - a database (set of sets of objects)

Returns:

the support of the item.

support

public static <S> double support(Collection<S> itemset,
                                 Collection<Collection<S>> database)

Returns the support of the given itemset wrt. the given database, i.e., the number of transactions of the database, which contain the given itemset, divided by the number of all transactions.

Parameters:

itemset - some set of objects

database - a database (set of sets of objects)

Returns:

the support of the itemset.

support

public double support(Collection<Collection<T>> database)

Returns the support of this rule wrt. the given database (a set of transactions), i.e. the support (frequency of occurrences) of the union of premise and conclusion in the database.

Parameters:

database - some set of transactions.

Returns:

the support of this rule.

confidence

public double confidence(Collection<Collection<T>> database)

Returns the confidence of this rule wrt. the given database (a set of transactions). More precisely, the support of this rule divided by the support of the premise alone.

Parameters:

database - some set of transactions.

Returns:

the confidence of the rule

toString

public String toString()

Overrides:

toString in class Object